Many items are susceptible to damage caused by excessive moisture. As used herein, the term “moisture” is intended to refer to water which is diffused or condensed, whether in liquid form or vapor form, from the ambient atmosphere. For instance, electrical and electronic items may be ruined or altered due to excessive moisture. Similarly, enclosed components, e.g., those contained in a housing, that undergo thermal cycling are susceptible to moisture related problems. Examples of enclosures which are susceptible to undesirable moisture include, for example, automotive headlamp units, electronics contained in enclosed housings, and other systems where on/off cycling of a heat source within an enclosure results in moisture build-up. One means of removing moisture from such enclosures is to provide greater airflow across, or through, the enclosure. However, when components are located in an enclosed housing it can be difficult to provide adequate airflow, where more traditional approaches to moisture reduction such as increased vent opening size can exacerbate problems such as enclosure contamination.
Another means of managing moisture in an enclosure is to place a drying agent or desiccant within the enclosure. As the terms “desiccants” or “drying agents” are used herein, they are intended to refer to any material which adsorbs water vapor from the air and is thereby able to reduce the moisture in the air in enclosed containers. However, desiccants have a limited capacity to adsorb moisture and require “regenerating” or removal of adsorbed moisture to continue functioning as a means to remove moisture in the air in an enclosure.